This should install the latest firmware, kernel and modbus server. Though unfortunately I really cannot say if that will fix the issue right at this very moment. I'll have a look into the code in the meanwhile, but please do see if the commands can fix the issue.

I will check the image on our download server to see if I can get it updated. If you do encounter any errors in the installation process then please do post here; the packages are tuned for a standard raspbian image, and may possibly not work properly with the older image from our server.

I believe I have now identified the problem. Unfortunately the update above will likely not work (though it should not cause any harm either) - I will have to generate a new version of our kernel driver. This will take approximately 2 days; apologies for any difficulties caused.

The issue is that the secondary analog output is missing a correct error code for reading, which the primary analog outputs do have. This causes a null pointer dereference and a subsequent crash. That said - the crash occurs because the IIO kernel subsystem does not check for a null pointer value where it is permitted, which it should, so it is possible that a general kernel update (which the commands above will try to perform) may help. However a definitive fix will be creating a dummy method to pass to the subsystem, which is something we should do regardless.

Thank you for the debugging, and apologies for any problems caused. I should say that aside from reading the particular file there doesn't appear to be anything else wrong with the unit, and it should otherwise perform as expected.

Thank you for the replies. As you said, the procedure actually failed on my UniPian image with an error saying that the neuron-kernel depends on raspberrypi-kernel of a more recent version. In any case, I will try the steps on a clean Raspbian image and check how it behaves.

In the mean time, are you guys planning to keep that UniPian image up to date? I'm asking this because I instructed OpenPLC users to download that image to install OpenPLC on their Neurons. If that image won't be getting updated regularly, I rather change the installation instructions to be based on a regular Raspbian image.

I've tried the steps on a blank new Raspbian image and encountered the same error while trying to install neuron-kernel:

root@raspberrypi:/home/pi# apt-get install neuron-kernel
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:
The following packages have unmet dependencies:
neuron-kernel : Depends: raspberrypi-kernel (= 1.20180919-1) but 1.20180924-1 is to be installed
E: Unable to correct problems, you have held broken packages.```